This application is based on and claims priority under 35 U.S.C. xc2xa7 119 with respect to Japanese Patent Application filed on Oct. 26, 2001, the entire content of which is incorporated herein by reference.
The present invention relates to a hydraulic brake device for a vehicle. More particularly, the present invention pertains to a hydraulic brake device for a vehicle which detects whether air is included in a hydraulic circuit.
Known hydraulic brake devices for a vehicle for providing the controlling force to vehicle wheels by supplying the hydraulic pressure in the hydraulic circuit to each wheel cylinder by generating the hydraulic pressure in the hydraulic circuit in accordance with the operational force of a brake pedal have been disclosed.
The foregoing known hydraulic brake devices include drawbacks that the operational feeling of the brake pedal is deteriorated when the air is included in the hydraulic circuit and that the sufficient braking force cannot be obtained even when performing the strong brake pedal operation when a full braking is required. In this case, a driver can notice that the air is included in the hydraulic circuit by a deterioration of the operational feeling of the brake pedal. Notwithstanding, in order to securely inform the driver of the air-containing in the hydraulic circuit with the hydraulic brake device for the vehicle, it is preferable to provide an air-containing detection means for detecting that the air is included in the hydraulic circuit and for alarming the driver.
The known hydraulic brake device disclosed in Japanese Patent Laid-Open Publication No. H03-45456 includes an auxiliary hydraulic source for generating and outputting a predetermined high pressure irrespective of a brake operation, a pressure regulator for regulating the hydraulic pressure supplied from the auxiliary hydraulic source in accordance with the brake operational amount to be outputted. With the known hydraulic brake device disclosed in the Japanese Patent Laid-Open Publication No. H03-45456, the braking force is provided to the vehicle wheels by supplying the hydraulic pressure supplied from the pressure regulator to each wheel cylinder.
With the known hydraulic brake device disclosed in the Japanese Patent Laid-Open Publication No. H03-45456, the brake pedal operational force is not directly affected by the hydraulic pressure in the hydraulic circuit. Thus, when the air is included in the hydraulic circuit, the operational feeling of the brake pedal does not decline and the driver does not have a chance to notice that the air is included in the hydraulic circuit. Accordingly, it is desired provide the air-containing detection means for detecting the air included in the hydraulic circuit and for alarming the driver when the air is included in the hydraulic circuit according to the type of the known hydraulic brake device disclosed in Japanese Patent Laid-Open Publication No. H03-45456.
A need thus exists for a hydraulic brake device for a vehicle providing braking force to wheels of the vehicle, which detects whether air is included in a hydraulic circuit thereof.
In light of the foregoing, the present invention provides a hydraulic brake device which includes a hydraulic pressure generating device for generating and outputting a hydraulic pressure in accordance with a brake operational amount, a wheel cylinder operated by the hydraulic pressure directly or indirectly supplied from the hydraulic pressure generating device for applying a braking force to a vehicle wheel, a brake operational amount detection means for detecting the brake operational amount, an output hydraulic pressure detection means for detecting an output hydraulic pressure outputted from the hydraulic pressure generating device, a hydraulic circuit for supplying the hydraulic pressure to the wheel cylinder, and an air-containing detection means for detecting air included in the hydraulic circuit by a response time relating to a rise of the output hydraulic pressure detected by the output hydraulic pressure detection means relative to a start of a rise of the brake operation amount detected by the brake operational amount detection means.
According to another aspect of the present invention, a hydraulic pressure device includes an accumulator for accumulating a hydraulic pressure, an auxiliary hydraulic source, the auxiliary hydraulic source having a hydraulic pump for supplying the hydraulic pressure to the accumulator and generating and outputting a high pressure within a predetermined range irrespective of a braking operation by intermittently actuating the hydraulic pump, a regulator for regulating the hydraulic pressure supplied from the auxiliary hydraulic source to output a regulated hydraulic pressure in accordance with a brake operational amount, a wheel cylinder operated by the hydraulic pressure directly or indirectly supplied from the regulator for applying a braking force to a wheel of a vehicle, an auxiliary hydraulic pressure detection means for detecting an auxiliary hydraulic pressure outputted from the auxiliary hydraulic source, an output hydraulic pressure detection means for detecting an output hydraulic pressure outputted from the regulator, a hydraulic circuit for supplying the hydraulic pressure to the wheel cylinder, and an air-containing detection means for detecting air included in the hydraulic circuit by a declining amount of the auxiliary hydraulic pressure detected by the auxiliary hydraulic pressure detection means relative to an increment of the output hydraulic pressure detected by the output hydraulic pressure detection means.
According to still another aspect of the present invention, a hydraulic brake device includes an accumulator for accumulating a hydraulic pressure, an auxiliary hydraulic source having a hydraulic pump for supplying the hydraulic pressure to the accumulator for generating and outputting a high pressure within a predetermined range irrespective of a braking operation by intermittently actuating the hydraulic pump, a regulator for regulating the hydraulic pressure supplied from the auxiliary hydraulic source in accordance with a brake operational amount to output a regulated hydraulic pressure, a wheel cylinder operated by the hydraulic pressure directly or indirectly supplied from the regulator to apply a braking force to a wheel of a vehicle, a brake operational amount detection means for detecting the braking operational amount, an auxiliary hydraulic pressure detection means for detecting an auxiliary hydraulic pressure outputted from the auxiliary hydraulic source, a hydraulic circuit for supplying the hydraulic pressure to the wheel cylinder, and an air-containing detection means for detecting air included in the hydraulic circuit by a declining amount of the auxiliary hydraulic pressure detected by the auxiliary hydraulic pressure detection means relative to an increment of the braking operational amount detected by the braking operational amount detection means under a non operation state of the hydraulic pump.
According to further aspect of the present invention, a hydraulic brake device includes an automatic hydraulic pressure generating device having an auxiliary hydraulic source for outputting a predetermined high pressure irrespective of a braking operation for regulating a hydraulic pressure supplied from the auxiliary hydraulic source irrespective of the braking operation to output a regulated hydraulic pressure, a wheel cylinder operated by the hydraulic pressure directly or indirectly supplied from the automatic hydraulic pressure generating device for applying a braking force to a wheel of a vehicle, an output hydraulic pressure detection means for detecting an output hydraulic pressure outputted from the automatic hydraulic pressure generating device, a hydraulic circuit for supplying the hydraulic pressure to the wheel cylinder, and an air-containing detection means for detecting air included in the hydraulic circuit by a response time relating to a rise of the output hydraulic pressure detected by the output hydraulic pressure detection means relative to a start of an operation of the automatic hydraulic pressure generating device.
According to still further aspect of the present invention, a hydraulic brake device includes an automatic hydraulic pressure generating device having an auxiliary hydraulic source for outputting a predetermined high pressure irrespective of a braking operation for regulating a hydraulic pressure supplied from the auxiliary hydraulic source irrespective of the braking operation to output a regulated hydraulic pressure, a wheel cylinder operated by the hydraulic pressure directly or indirectly supplied from the automatic hydraulic pressure generating device for applying a braking force to a wheel of a vehicle, an output hydraulic pressure detection means for detecting an output hydraulic pressure outputted from the automatic hydraulic pressure generating device, a hydraulic circuit for supplying the hydraulic pressure to the wheel cylinder, and an air-containing detection means for detecting air included in the hydraulic circuit by an increment of the output hydraulic pressure detected by the output hydraulic pressure detection means after elapsing a predetermined time from starting an operation of the automatic hydraulic pressure generating device.
According to still further aspect of the present invention, a hydraulic brake device includes an automatic hydraulic pressure generating device, the automatic hydraulic pressure generating device having an accumulator for accumulating a hydraulic pressure, a hydraulic pump for supplying a hydraulic pressure to the accumulator, and an auxiliary hydraulic source for generating and outputting a high pressure within a predetermined range irrespective of a braking operation by intermittently actuating the hydraulic pump for regulating the hydraulic pressure supplied from the auxiliary hydraulic source irrespective of the braking operation to output a regulated hydraulic pressure. The hydraulic brake device further includes a wheel cylinder operated by the hydraulic pressure directly or indirectly supplied from the automatic hydraulic pressure generating device for applying a braking force to a wheel of a vehicle, an auxiliary hydraulic pressure detection means for detecting an auxiliary hydraulic pressure outputted from the auxiliary hydraulic source, an outputted hydraulic pressure detection means for detecting an output hydraulic pressure outputted from the automatic hydraulic pressure generating device, a hydraulic circuit for supplying the hydraulic pressure to the wheel cylinder, and an air-containing detection means for detecting air included in the hydraulic circuit by a declining of the auxiliary hydraulic pressure detected by the auxiliary hydraulic pressure detection means relative to an increment of the output hydraulic pressure detected by the output hydraulic pressure detection means after starting an operation of the automatic hydraulic pressure generating device under a non-operation state of the hydraulic pump.